This invention relates to a device for generating the audio information of a set of characters which comprises a first sub-set of small (lower case) letters and a second sub-set of upper case capital letters, said device comprising a data-processor unit to which there are connected a first memory for the storage of speech data and a second memory for the storage of characters presented thereto. The data-processor unit comprises control means for forming, on the basis of said speech data, a speech pattern for a character presented in order to control a speech generator which is connected to the first memory, said data-processor unit also comprising recognition means for recognizing from the characters presented those characters which belong to said second sub-set and for introducing a first modification in the speech pattern for the characters belonging to the second sub-set, while maintaining their identity.
A device of this kind is known from U.S. Pat. No. 4,060,848. Therein, inter alia, a calculator and a typewriter are described in which the characters presented by an operator via a keyboard connected to the device are converted into speech. The operator can thus check whether the correct information has been inputted, without taking his vision from the keyboard or from the text to be typed. The characters presented are stored in the second memory. Under the control of the data-processor unit, a speech pattern is formed on the basis of the speech data stored in the first memory for a character presented, the speech generating speech on the basis of said speech pattern. The data-processor unit comprises recognition means for distinguishing the capital letters from the other characters in the characters presented.
For a capital letter a modification is introduced in the speech pattern. This modification consists of the addition of the prefix "CAP".
It is a drawback of such a device that the addition of said prefex adversely affects the pronunciation time and hence the associated pronunciation rate. It is further drawback of such a device that all speech generated is pronounced with the same speech pattern. Due to this monotonous pronunciation, it is difficult to distinguish the individual words in a sentence.